1. Field of the Invention
The present invention relates to target sights to be used particularly in bow hunting and other archery activities, and more particularly to sights which include range finders.
2. Description of the Related Art
Many attempts have been made previously to design and produce a sight that will compensate or adjust the sight for varying distances between a projectile launcher, such as an archery bow, and the intended target. In such designs, the failure to provide the required degree of accuracy and ease of use have prevented the designs from making any significant impact in the archery industry. The cost of manufacture of such designs and the projected retail prices have also hindered any widespread adoption of designs proposed to date.
The relatively recent introduction and wide popularity of compound bows has further added to the difficulty of designing a combined sight and range finder. Compound bows allow for a wide variety of arrow speeds (initial velocity), both among different bow designs and among different users of particular types of bow. The range of possible arrow speeds with the bows in use today is from about 150 feet per second (fps) to about 350 fps. This range of possible arrow speeds has made certain designs useful only for a small variety of available bows. The required accuracy cannot be realized across this entire range.
Other designs have proven to be too cumbersome to adjust to different target sizes at varying distances, requiring slow or complicated operations to adjust for these criteria, as well as for varying arrow speeds.
For example, U.S. Pat. No. 3,666,368, issued to Sprandel, discloses an archery sight and range finder which employs a trigger mechanism to slide two sight bars along a vertical track, with one sight bar moving a greater distance than the other for a given pull of the trigger. This enables the sight bars to be moved farther apart and closer together, as appropriate, to frame targets located at different distances. The patent discloses that the length of one of the links can be adjusted by turning a finger knob to accommodate the use of the sight for different sized targets. This adjustment is fairly complicated to achieve, and is not useful for making such adjustments in the field when encountering game or other targets of varying sizes. In addition, the use of a bulls-eye sight disposed on the lower bar, and designed to be used to sight between the bars, limits the distances at which the sight may be used. It also introduces potential error due to the fact that the bulls-eye sight is at a fixed distance from the lower bar, whereas the actual target area (generally, the heart region) on a given type of game will be at a different height relative to the upper and lower bars framing the target. Further, the patent does not address any means by which the sight and range finder can be adapted for use with varying arrow speeds which are a result of the various bow designs now available, the various arrow designs, and the differing manner in which the bows are used by archers (e.g., amount of string pull to “full draw”).
The Reichert patent, U.S. Pat. No. 6,061,919, addresses the more modern-day concern as to how to adapt a sight and range finder to varying arrow speeds, in addition to varying target sizes. The solution proposed by Reichert is to change out cam elements in the device to make these adjustments. An initial cam selection process may be made for a given bow used by a given archer, however, that process is time consuming and tedious. Beyond that, the requirement to then change out cam components as an adjustment for varying target sizes means that this design is not well suited for adjustments being made in the field upon encountering game or other targets of varying sizes.
It is a principal object of the present invention to provide a target sight which overcomes the disadvantages of the designs previously proposed.
More specifically, it is a principal object of the present invention to provide a combined sight and range finder which can be set up or calibrated for a wide variety of bow speeds/arrow speeds, in a relatively simple manner.
It is a further principal object of the present invention to provide a combined sight and range finder which can be quickly adjusted in the field for various target sizes that may be encountered.
It is yet a further principal object of the present invention to provide a highly reliable and accurate combined sight and range finder which can provide accuracy to distances on the order of 70-75 or more yards.
It is an additional principal object of the invention to provide a simple sight/range finder set up procedure which takes into account the specific bow speed/arrow speed of each individual bow and shooter.